/* $Header: /roq/tiff/tif_zip.c 1     11/02/99 4:40p Zaphod $ */



/*

 * Copyright (c) 1995-1996 Sam Leffler

 * Copyright (c) 1995-1996 Silicon Graphics, Inc.

 *

 * Permission to use, copy, modify, distribute, and sell this software and 

 * its documentation for any purpose is hereby granted without fee, provided

 * that (i) the above copyright notices and this permission notice appear in

 * all copies of the software and related documentation, and (ii) the names of

 * Sam Leffler and Silicon Graphics may not be used in any advertising or

 * publicity relating to the software without the specific, prior written

 * permission of Sam Leffler and Silicon Graphics.

 * 

 * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, 

 * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY 

 * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.  

 * 

 * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR

 * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,

 * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,

 * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF 

 * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 

 * OF THIS SOFTWARE.

 */



#include "tiffiop.h"

#ifdef ZIP_SUPPORT

/*

 * TIFF Library.

 *

 * ZIP (aka Deflate) Compression Support

 *

 * This file is simply an interface to the zlib library written by

 * Jean-loup Gailly and Mark Adler.  You must use version 1.0 or later

 * of the library: this code assumes the 1.0 API and also depends on

 * the ability to write the zlib header multiple times (one per strip)

 * which was not possible with versions prior to 0.95.  Note also that

 * older versions of this codec avoided this bug by supressing the header

 * entirely.  This means that files written with the old library cannot

 * be read; they should be converted to a different compression scheme

 * and then reconverted.

 *

 * The data format used by the zlib library is described in the files

 * zlib-3.1.doc, deflate-1.1.doc and gzip-4.1.doc, available in the

 * directory ftp://ftp.uu.net/pub/archiving/zip/doc.  The library was

 * last found at ftp://ftp.uu.net/pub/archiving/zip/zlib/zlib-0.99.tar.gz.

 */

#include "tif_predict.h"

#include "zlib.h"



#include <stdio.h>

#include <assert.h>



/*

 * Sigh, ZLIB_VERSION is defined as a string so there's no

 * way to do a proper check here.  Instead we guess based

 * on the presence of #defines that were added between the

 * 0.95 and 1.0 distributions.

 */

#if !defined(Z_NO_COMPRESSION) || !defined(Z_DEFLATED)

#error "Antiquated ZLIB software; you must use version 1.0 or later"

#endif



/*

 * State block for each open TIFF

 * file using ZIP compression/decompression.

 */

typedef	struct {

	TIFFPredictorState predict;

	z_stream	stream;

	int		zipquality;		/* compression level */

	int		state;			/* state flags */

#define	ZSTATE_INIT	0x1		/* zlib setup successfully */



	TIFFVGetMethod	vgetparent;		/* super-class method */

	TIFFVSetMethod	vsetparent;		/* super-class method */

} ZIPState;



#define	ZState(tif)		((ZIPState*) (tif)->tif_data)

#define	DecoderState(tif)	ZState(tif)

#define	EncoderState(tif)	ZState(tif)



static	int ZIPEncode(TIFF*, tidata_t, tsize_t, tsample_t);

static	int ZIPDecode(TIFF*, tidata_t, tsize_t, tsample_t);



static int

ZIPSetupDecode(TIFF* tif)

{

	ZIPState* sp = DecoderState(tif);

	static char module[] = "ZIPSetupDecode";



	assert(sp != NULL);

	if (inflateInit(&sp->stream) != Z_OK) {

		TIFFError(module, "%s: %s", tif->tif_name, sp->stream.msg);

		return (0);

	} else {

		sp->state |= ZSTATE_INIT;

		return (1);

	}

}



/*

 * Setup state for decoding a strip.

 */

static int

ZIPPreDecode(TIFF* tif, tsample_t s)

{

	ZIPState* sp = DecoderState(tif);



	(void) s;

	assert(sp != NULL);

	sp->stream.next_in = tif->tif_rawdata;

	sp->stream.avail_in = tif->tif_rawcc;

	return (inflateReset(&sp->stream) == Z_OK);

}



static int

ZIPDecode(TIFF* tif, tidata_t op, tsize_t occ, tsample_t s)

{

	ZIPState* sp = DecoderState(tif);

	static char module[] = "ZIPDecode";



	(void) s;

	assert(sp != NULL);

	sp->stream.next_out = op;

	sp->stream.avail_out = occ;

	do {

		int state = inflate(&sp->stream, Z_PARTIAL_FLUSH);

		if (state == Z_STREAM_END)

			break;

		if (state == Z_DATA_ERROR) {

			TIFFError(module,

			    "%s: Decoding error at scanline %d, %s",

			    tif->tif_name, tif->tif_row, sp->stream.msg);

			if (inflateSync(&sp->stream) != Z_OK)

				return (0);

			continue;

		}

		if (state != Z_OK) {

			TIFFError(module, "%s: zlib error: %s",

			    tif->tif_name, sp->stream.msg);

			return (0);

		}

	} while (sp->stream.avail_out > 0);

	if (sp->stream.avail_out != 0) {

		TIFFError(module,

		    "%s: Not enough data at scanline %d (short %d bytes)",

		    tif->tif_name, tif->tif_row, sp->stream.avail_out);

		return (0);

	}

	return (1);

}



static int

ZIPSetupEncode(TIFF* tif)

{

	ZIPState* sp = EncoderState(tif);

	static char module[] = "ZIPSetupEncode";



	assert(sp != NULL);

	if (deflateInit(&sp->stream, sp->zipquality) != Z_OK) {

		TIFFError(module, "%s: %s", tif->tif_name, sp->stream.msg);

		return (0);

	} else {

		sp->state |= ZSTATE_INIT;

		return (1);

	}

}



/*

 * Reset encoding state at the start of a strip.

 */

static int

ZIPPreEncode(TIFF* tif, tsample_t s)

{

	ZIPState *sp = EncoderState(tif);



	(void) s;

	assert(sp != NULL);

	sp->stream.next_out = tif->tif_rawdata;

	sp->stream.avail_out = tif->tif_rawdatasize;

	return (deflateReset(&sp->stream) == Z_OK);

}



/*

 * Encode a chunk of pixels.

 */

static int

ZIPEncode(TIFF* tif, tidata_t bp, tsize_t cc, tsample_t s)

{

	ZIPState *sp = EncoderState(tif);

	static char module[] = "ZIPEncode";



	(void) s;

	sp->stream.next_in = bp;

	sp->stream.avail_in = cc;

	do {

		if (deflate(&sp->stream, Z_NO_FLUSH) != Z_OK) {

			TIFFError(module, "%s: Encoder error: %s",

			    tif->tif_name, sp->stream.msg);

			return (0);

		}

		if (sp->stream.avail_out == 0) {

			tif->tif_rawcc = tif->tif_rawdatasize;

			TIFFFlushData1(tif);

			sp->stream.next_out = tif->tif_rawdata;

			sp->stream.avail_out = tif->tif_rawdatasize;

		}

	} while (sp->stream.avail_in > 0);

	return (1);

}



/*

 * Finish off an encoded strip by flushing the last

 * string and tacking on an End Of Information code.

 */

static int

ZIPPostEncode(TIFF* tif)

{

	ZIPState *sp = EncoderState(tif);

	static char module[] = "ZIPPostEncode";

	int state;



	sp->stream.avail_in = 0;

	do {

		state = deflate(&sp->stream, Z_FINISH);

		switch (state) {

		case Z_STREAM_END:

		case Z_OK:

		    if (sp->stream.avail_out != tif->tif_rawdatasize) {

			    tif->tif_rawcc =

				tif->tif_rawdatasize - sp->stream.avail_out;

			    TIFFFlushData1(tif);

			    sp->stream.next_out = tif->tif_rawdata;

			    sp->stream.avail_out = tif->tif_rawdatasize;

		    }

		    break;

		default:

		    TIFFError(module, "%s: zlib error: %s",

			tif->tif_name, sp->stream.msg);

		    return (0);

		}

	} while (state != Z_STREAM_END);

	return (1);

}



static void

ZIPCleanup(TIFF* tif)

{

	ZIPState* sp = ZState(tif);

	if (sp) {

		if (tif->tif_mode == O_RDONLY)

			inflateEnd(&sp->stream);

		else

			deflateEnd(&sp->stream);

		_TIFFfree(sp);

		tif->tif_data = NULL;

	}

}



static int

ZIPVSetField(TIFF* tif, ttag_t tag, va_list ap)

{

	ZIPState* sp = ZState(tif);

	static char module[] = "ZIPVSetField";



	switch (tag) {

	case TIFFTAG_ZIPQUALITY:

		sp->zipquality = va_arg(ap, int);

		if (tif->tif_mode != O_RDONLY && (sp->state&ZSTATE_INIT)) {

			if (deflateParams(&sp->stream,

			    sp->zipquality, Z_DEFAULT_STRATEGY) != Z_OK) {

				TIFFError(module, "%s: zlib error: %s",

				    tif->tif_name, sp->stream.msg);

				return (0);

			}

		}

		return (1);

	default:

		return (*sp->vsetparent)(tif, tag, ap);

	}

	/*NOTREACHED*/

}



static int

ZIPVGetField(TIFF* tif, ttag_t tag, va_list ap)

{

	ZIPState* sp = ZState(tif);



	switch (tag) {

	case TIFFTAG_ZIPQUALITY:

		*va_arg(ap, int*) = sp->zipquality;

		break;

	default:

		return (*sp->vgetparent)(tif, tag, ap);

	}

	return (1);

}



static const TIFFFieldInfo zipFieldInfo[] = {

    { TIFFTAG_ZIPQUALITY,	 0, 0,	TIFF_ANY,	FIELD_PSEUDO,

      TRUE,	FALSE,	"" },

};

#define	N(a)	(sizeof (a) / sizeof (a[0]))



int

TIFFInitZIP(TIFF* tif, int scheme)

{

	ZIPState* sp;



	assert(scheme == COMPRESSION_DEFLATE);



	/*

	 * Allocate state block so tag methods have storage to record values.

	 */

	tif->tif_data = (tidata_t) _TIFFmalloc(sizeof (ZIPState));

	if (tif->tif_data == NULL)

		goto bad;

	sp = ZState(tif);

	sp->stream.zalloc = NULL;

	sp->stream.zfree = NULL;

	sp->stream.opaque = NULL;

	sp->stream.data_type = Z_BINARY;



	/*

	 * Merge codec-specific tag information and

	 * override parent get/set field methods.

	 */

	_TIFFMergeFieldInfo(tif, zipFieldInfo, N(zipFieldInfo));

	sp->vgetparent = tif->tif_vgetfield;

	tif->tif_vgetfield = ZIPVGetField;	/* hook for codec tags */

	sp->vsetparent = tif->tif_vsetfield;

	tif->tif_vsetfield = ZIPVSetField;	/* hook for codec tags */



	/* Default values for codec-specific fields */

	sp->zipquality = Z_DEFAULT_COMPRESSION;	/* default comp. level */

	sp->state = 0;



	/*

	 * Install codec methods.

	 */

	tif->tif_setupdecode = ZIPSetupDecode;

	tif->tif_predecode = ZIPPreDecode;

	tif->tif_decoderow = ZIPDecode;

	tif->tif_decodestrip = ZIPDecode;

	tif->tif_decodetile = ZIPDecode;

	tif->tif_setupencode = ZIPSetupEncode;

	tif->tif_preencode = ZIPPreEncode;

	tif->tif_postencode = ZIPPostEncode;

	tif->tif_encoderow = ZIPEncode;

	tif->tif_encodestrip = ZIPEncode;

	tif->tif_encodetile = ZIPEncode;

	tif->tif_cleanup = ZIPCleanup;

	/*

	 * Setup predictor setup.

	 */

	(void) TIFFPredictorInit(tif);

	return (1);

bad:

	TIFFError("TIFFInitZIP", "No space for ZIP state block");

	return (0);

}

#endif /* ZIP_SUPORT */

